共查询到20条相似文献,搜索用时 10 毫秒
1.
JETP Letters - The luminescence spectra due to recombination of two-dimensional electrons with optically excited holes have been studied in a wide range of electron filling factors in the... 相似文献
2.
O. V. Volkov V. E. Zhitomirskii I. V. Kukushkin K. von Klitzing K. Eberl 《JETP Letters》1997,65(1):38-44
The recombination radiation spectra of two-dimensional electrons in an asymmetrically doped GaAs/AlGaAs quantum well are investigated
at different temperatures and laser-excitation energies. At low temperatures and in high magnetic fields the recombination
lines of the electrons from completely filled Landau levels are split into narrow sublevels. It is shown that this fine structure
of the Landau levels is due to the presence of excitonic effects in the initial and final states of the photoexcited system.
It is demonstrated that the recombination process is accompanied by the excitation of intersubband and cyclotron magnetoplasma
modes.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 1, 38–43 (10 January 1997) 相似文献
3.
S. V. Iordanski 《JETP Letters》2014,99(9):523-526
It is shown that the thermodynamic instability at the half filling of L1 leads to the vortex lattice formation with the electronic spectrum analogous to that of graphene with two Dirac-Fermi points on Brillouin cell boundary. This result is used for the explanation of the observed current generated by a surface acoustic wave in the heterostructure on the surface of piezoelectric GaAs. Using the existence of two Fermi points instead of a Fermi surface suggested in the previous theoretical works, permit the explanation of the experimental results. 相似文献
4.
O. V. Volkov V. E. Zhitomirskii I. V. Kukushkin K. von Klitzing K. Eberl 《JETP Letters》1996,64(10):774-779
A study is made of the temperature dependence of the magnetooscillations of the recombination radiation of 2D electrons from
the photoexcited size-quantization subband in an isolated GaAs/AlGaAs quantum well. It is shown that at high temperatures
(T>10 K) the period of the oscillations is determined by the ratio of the intersubband energy splitting and the sum of the electron
and hole cyclotron energies. It is found that as the temperature decreases (T<5 K), a new series of oscillations (with the same period but with a larger phase shift), which are associated with the appearance
of excitonic states under the Landau levels, appears.
Pis’ma Zh. éksp. Teor. Fiz. 64, No. 10, 719–724 (25 November 1996) 相似文献
5.
N. G. Goncharova A. P. Dolgodvorov S. I. Sergeeva 《Moscow University Physics Bulletin》2014,69(3):237-242
The rigidities of collective nuclear oscillations were calculated for 44 even-even atomic nuclei and compared to the charge radii. Correlations between the rigidity maxima and the minimal values of the r 0 parameter were revealed. These correlations were attributed to the high surface tension in nuclei with filled neutron shells and the associated increase in pressure on nuclear matter. 相似文献
6.
H. Nakata T. Murakami K. Fujii T. Ohyama 《Physica E: Low-dimensional Systems and Nanostructures》2006,34(1-2):296
We observed photoluminescence (PL) and photoluminescence excitation (PLE) spectra due to shake-up processes of recombination of two-dimensional electrons and free excitons in a modulation-doped GaAs quantum well at He temperatures. One of the processes is that when an electron recombines with a hole, another electron is excited from the conduction band in GaAs to that in AlGaAs. The other process is that a hole is excited from an acceptor level or the valence band in GaAs to the valence band in AlGaAs during recombination. The electron process is observed in both PL and PLE spectra while the hole process only in the PL spectra. The excitation-intensity dependence of the peak intensity of hole-excited PL is almost quadratic, indicating three-carrier process in the shake-up process. The band offsets of the conduction and valence bands are estimated to be 220 and 146 meV, respectively. 相似文献
7.
The lifetime of electrons in the first excited Landau level of n-GaAs is determined from a combination of measurements of far infrared cyclotron resonance induced absorption and conductivity change. Values of T1 of the order of 10?8s for densities of excited electrons of 1011 cm?3 and a temperature dependence of T?2.7 are found. An upper limit for the N = 0 Landau level to donor recombination time of the order of 10?9s was derived from pulsed conductivity measurements. 相似文献
8.
In the framework of the quantum statistical physics it was shown that direct subtraction of the electron interaction energy
in a magnetic field from the kinetic energy or its addition to the latter in the strength function contradicts to the well-known
fact according to which the magnetic field does no positive work over a charged particle.
Byelorussian State University, Brest State University. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No.
6, pp. 31–35, June, 2000. 相似文献
9.
F. Despa R. S. Berry 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2003,24(1-3):37-40
Interpretive theoretical tools prove valuable in guiding
the analysis of experiments in the realm of atomic clusters.
Here, we review basic elements of an analytic approach that
makes it possible to find and visualize the effective
electrostatic potential and Coulomb correlations in multicenter
problems. To illustrate the utility of these concepts we apply
them to exploring molecular-doped metallic clusters. This study
is aiming at a systematic, visual assessment of changes induced
in screening, Coulomb correlation and effective potential by
varying the charge of the electronegative impurity and its
position in the cluster cage. 相似文献
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Summary The response function for magnetic neutron scattering off electrons forming a one-component plasma, or jellium model, subject
to a steady magnetic field, is calculated in the semi-classical limit in which Boltzmann statistics apply to the electron
states. A complete expression for the response of an ideal plasma is given in a compact, closed form, amenable to numerical
investigation, and including the dependence on electron parameters such as effective mass and gyromagnetic ratio. Effects
due to the Coulomb interaction are discussed within the limitations of the random phase approximation. The theoretical results
are used to predict the conditions that must obtain for the observation of neutron excitation of Landau and collective modes.
Riassunto La funzione di risposta per lo scattering magnetico dei neutroni dagli elettroni che forma un plasma ad un componente, o modello di jellio, soggetto ad un campo magnetico fisso, è calcolata nel limite semiclassico nel quale la statistica di Boltzmann si applichi agli stati elettronici. Si dà un’espressione completa per la risposta di un plasma ideale in una forma compatta e chiusa adatta alla ricerca numerica e che include la dipendenza dai parametri elettronici come la massa efficace ed il rapporto giromagnetico. Si discutono gli effetti dovuti all’interazione di Coulomb entro i limiti dell’approssimazione di fase random. I risultati teorici sono usati per prevedere le condizioni che devono essere ottenute dall’osservazione dell’eccitazione dei neutroni di Landau e dei modi collettivi.相似文献
13.
V. L. Korotkikh 《Physics of Atomic Nuclei》2009,72(11):1951-1959
Experimental results concerning heavy-ion collisions studied by means of the Relativistic Heavy-Ion Collider (RHIC) at an
energy of 100 GeV per nucleon and showing manifestations of collective effects are surveyed. These effects are interpreted
as a consequence of the formation of a dense thermalized medium referred to as quark-gluon plasma (strongly interacting quark-gluon
plasma, quark-gluon matter, parton medium). An azimuthal anisotropy of particles, the suppression of the particle yield at
high transverse momenta in relation to proton-proton collisions, and a change in the shape of the peak from a hadron jet in
nucleus-nucleus collisions are spectacular manifestations of collective effects. 相似文献
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15.
M. V. Lebedev I. V. Kukushkin O. V. Volkov A. L. Parakhonskii J. H. Smet K. von Klitzing 《JETP Letters》2003,77(6):295-299
Correlations have been studied between the recombination radiation intensities of a two-dimensional electron gas measured at different points of the sample with giant luminescence fluctuations in the quantum Hall effect regime. It has been found that the correlation of the radiation intensities measured under these conditions at different points of the sample separated by a distance of 1–3 mm is close to unity and disappeared in a threshold way with increasing temperature. It is shown that macroscopic spatial correlations also disappear if the electron system is artificially divided into two subsystems not connected with each other. 相似文献
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17.
P. I. Didenko A. A. Efremov Yu. A. Kudryavtsev 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2012,6(1):182-186
The energy spectra of 46−50Ti+ titanium isotope secondary ions are investigated via steady-state oxygen ion beam sputtering of FeTiO3 ilmenite and UTi2O6 brannerite samples. The effect of these samples’ phase composition on the formation of specific short-range order statistics
on the sputtered surface as well as the influence of various factors on the form of the energy spectra of these matrices are
analyzed. The nature of the differences between the energy spectra of Ti+ and U+ secondary ions is considered. The isotopic composition of the elements in the investigated samples and the correlation between
the type of isotope and the nature of its short-range order are analyzed. 相似文献
18.
We discuss the low-energy dissociative recombination of H+3, which strongly influences the abundance of this ion in diffuse interstellar molecular clouds. The kinetic couplings between the ionization continuum and the dissociative ground state of H3 have been used as input to a two-dimensional wave packet calculation of dissociation dynamics. The cross section obtained for direct dissociative recombination is much smaller than the latest experimental results. However, a multichannel quantum defect treatment shows that an indirect mechanism via bound Rydberg states of H3 prevails for this process. 相似文献
19.
Eshed A Goktepeli S Koymen AR Kim S Chen WC O'Kelly DJ Sterne PA Weiss AH 《Physical review letters》2002,89(7):075503
The first gamma spectra associated with the annihilation of positrons with individual core levels (Cu 3p and Ag 4p) are presented. The spectra were obtained by measuring the energy of gamma rays time coincident with Auger electrons emitted as a result of positrons annihilating with a selected core level. Relativistic calculations show good agreement with experiment over a limited range of momenta. However, statistically significant differences indicate that the measurements can provide an impetus to new calculations of many body effects in positron-core electrons annihilation. 相似文献
20.
《Physics letters. A》1968,26(3):119-120
Through the comparison of two successful theoretical interpretations of the plasmon satellite in soft X-ray spectra, a better physical understanding of the satellite emission is obtained. 相似文献